diff --git a/xUnitStudy.Model/xUnitStudy.Model.csproj b/xUnitStudy.Model/xUnitStudy.Model.csproj
index d6a6233..0c99b2e 100644
--- a/xUnitStudy.Model/xUnitStudy.Model.csproj
+++ b/xUnitStudy.Model/xUnitStudy.Model.csproj
@@ -46,6 +46,9 @@
     <Compile Include="Student.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="xUnitStudy\AssertEqualDemo.cs" />
+    <Compile Include="xUnitStudy\IPerson.cs" />
+    <Compile Include="xUnitStudy\Person.cs" />
+    <Compile Include="xUnitStudy\Teacher.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="packages.config" />
diff --git a/xUnitStudy.Model/xUnitStudy/IPerson.cs b/xUnitStudy.Model/xUnitStudy/IPerson.cs
new file mode 100644
index 0000000..8b7e9ef
--- /dev/null
+++ b/xUnitStudy.Model/xUnitStudy/IPerson.cs
@@ -0,0 +1,19 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace xUnitStudy.Model
+{
+    public interface IPerson
+    {
+        int Id { get; set; }
+
+        string FirstName { get; set; }
+
+        string LastName { get; set; }
+
+        string GetFullName();
+    }
+}
diff --git a/xUnitStudy.Model/xUnitStudy/Person.cs b/xUnitStudy.Model/xUnitStudy/Person.cs
new file mode 100644
index 0000000..3a38985
--- /dev/null
+++ b/xUnitStudy.Model/xUnitStudy/Person.cs
@@ -0,0 +1,31 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace xUnitStudy.Model
+{
+    public class Person:IPerson,IEqualityComparer<Person>
+    {
+        public int Id { get; set; }
+
+        public string FirstName { get; set; }
+
+        public string LastName { get; set; }
+
+        public string GetFullName()
+        {
+            return FirstName + "_" + LastName;
+        }
+        public bool Equals(Person x, Person y)
+        {
+            return x.Id == y.Id;
+        }
+
+        public int GetHashCode(Person obj)
+        {
+           return  obj.Id;
+        }
+    }
+}
diff --git a/xUnitStudy.Model/xUnitStudy/Teacher.cs b/xUnitStudy.Model/xUnitStudy/Teacher.cs
new file mode 100644
index 0000000..dde6c6f
--- /dev/null
+++ b/xUnitStudy.Model/xUnitStudy/Teacher.cs
@@ -0,0 +1,13 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace xUnitStudy.Model
+{
+    public class Teacher:Person
+    {
+        public int Grade { get; set; }
+    }
+}
diff --git a/xUnitStudy.WebApi.Test/UseXUnitAssertTest.cs b/xUnitStudy.WebApi.Test/UseXUnitAssertTest.cs
index 34ca880..52c1627 100644
--- a/xUnitStudy.WebApi.Test/UseXUnitAssertTest.cs
+++ b/xUnitStudy.WebApi.Test/UseXUnitAssertTest.cs
@@ -1,7 +1,9 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using Xunit;
 using xUnitStudy.Model;
@@ -21,8 +23,6 @@ namespace xUnitStudy.WebApi.Test
         }
         #endregion
 
-        
-
         #region Equal
         [Fact]
         public void Equal_String_Test()
@@ -607,6 +607,7 @@ namespace xUnitStudy.WebApi.Test
         }
         #endregion
 
+        #region Null|Empty
         [Fact]
         public void Empty_Test()
         {
@@ -651,7 +652,9 @@ namespace xUnitStudy.WebApi.Test
 
             Assert.NotNull(new List<string>() { "first", "second" });
         }
+        #endregion
 
+        #region Type|Assignable
         [Fact]
         public void IsType_Test()
         {
@@ -689,7 +692,355 @@ namespace xUnitStudy.WebApi.Test
         {
             //可以从指定的类型派生
             Assert.IsAssignableFrom<object>(22);
+
+
+            Person person = new Person() { Id = 1, FirstName = "first", LastName = "last" };
+            Assert. //接口派生
+                    IsAssignableFrom<IPerson>(person);
+
+            Teacher teacher = new Teacher() { Id = 1, FirstName = "first", LastName = "last", Grade = 2 };
+            Assert. //类继承
+                    IsAssignableFrom<Person>(teacher);
+
+            Assert //接口派生
+                  .IsAssignableFrom<IPerson>(teacher);
+
+
+            Assert //万源归宗
+                  .IsAssignableFrom<object>(teacher);
+        }
+
+        /// <summary>
+        /// 断言非派生、继承关系
+        /// Assert.False(obj is Type)替代
+        /// </summary>
+        [Fact]
+        public void IsNotAssignableFrom_Test()
+        {
+            // Assert.False(obj is Type) 替代
+
+            //可以从指定的类型派生
+            Assert.False(88 is String);
+            Assert.False(new object() is int);
+
+            Person person = new Person() { Id = 1, FirstName = "first", LastName = "last" };
+            Teacher teacher = new Teacher() { Id = 2, FirstName = "first", LastName = "last", Grade = 2 };
+            IPerson person2 = new Person() { Id = 3, FirstName = "first", LastName = "last" };
+
+            Assert.False(person is Teacher);
+            Assert.False(person2 is Teacher);
+        }
+        #endregion
+
+        #region Contains For String
+                [Fact]
+        public void Contains_String_Test()
+        {
+            Assert.Contains("hello", "hello,world.");
+            Assert.Contains("llo", "hello,world.");
+            Assert.Contains("world", "hello,world.");
+        }
+
+        [Fact]
+        public void Contains_String_Comparison_Ordinal_Test()
+        {
+            //StringComparison.Ordinal 二进制比较：最快,最严格
+            //进行非语言(non-linguistic)上的比较,对两个字符串进行byte级别的比较,比较结果严格而准确,性能非常好。
+            Assert.Contains("hello", "hello,world", StringComparison.Ordinal);
+            Assert.Contains("llo", "hello,world", StringComparison.Ordinal);
+            Assert.Contains("orld", "hello,world", StringComparison.Ordinal);
+        }
+
+        [Fact]
+        public void Contains_String_Comparison_OrdinalIgnoreCase_Test()
+        {
+            //StringComparison.OrdinalIgnoreCase与StringComparison.Ordinal相同，只是不区分大小写
+            Assert.Contains("hello", "Hello,World", StringComparison.OrdinalIgnoreCase);
+            Assert.Contains("llo", "Hello,World", StringComparison.OrdinalIgnoreCase);
+            Assert.Contains("orld", "Hello,World", StringComparison.OrdinalIgnoreCase);
+        }
+
+        [Fact]
+        public void Contains_String_Comparison_CurrentCulture_Test()
+        {
+            //StringComparison.CurrentCulture 默认的比较方式：使用区域敏感排序规则和当前区域比较字符串
+            //在当前的区域信息下进行比较,这是String.Compare在没有指定StringComparison的时候默认的比较方式
+
+            Assert.Contains("", "", StringComparison.CurrentCulture);
+            Assert.Contains("orl", "hello,world", StringComparison.CurrentCulture);
+
+            //设置特定区域
+            string s1 = "encyclopædia";
+            string s2 = "encyclopaedia";
+
+            //当前的区域信息是美国:s1与s2是相等的。
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
+            Assert.Contains(s1, s2, StringComparison.CurrentCulture);
+
+            //当前的区域信息是se-SE，s1与s2是相等的
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("se-SE");
+            Assert.DoesNotContain(s1, s2, StringComparison.CurrentCulture);
+        }
+
+        [Fact]
+        public void Contains_String_Comparison_CurrentCultureIgnoreCase_Test()
+        {
+            //用法同：StringComparison.CurrentCulture，只是不区分大小写
+
+            Assert.Contains("A", "aBB", StringComparison.CurrentCultureIgnoreCase);
+            Assert.Contains("worl", "Hello,World", StringComparison.CurrentCultureIgnoreCase);
+
+            //设置特定区域
+            string s1 = "Encyclopædia";
+            string s2 = "encyclopaediA";
+
+            //当前的区域信息是美国:s1与s2是相等的。
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
+            Assert.Contains(s1, s2, StringComparison.CurrentCultureIgnoreCase);
+
+            //当前的区域信息是se-SE，s1与s2是相等的
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("se-SE");
+            Assert.DoesNotContain(s1, s2, StringComparison.CurrentCultureIgnoreCase);
+        }
+
+        [Fact]
+        public void Contains_String_Comparison_InvariantCulture_Test()
+        {
+            //StringComparison.InvariantCulture：使用区域敏感排序规则和固定区域比较字符串
+            //在任何系统中(不同的culture)比较都将得到相同的结果,他是使用CultureInfo.InvariantCulture的静态成员CompareInfo来进行比较操作的.
+            //StringComparison.InvariantCultureIgnoreCase与StringComparison.InvariantCulture，只是忽略大小写
+
+            Assert.Contains("ping", "ping", StringComparison.InvariantCulture);
+            Assert.Contains("p", "ping", StringComparison.InvariantCulture);
+            Assert.Contains("in", "ping", StringComparison.InvariantCulture);
+            Assert.Contains("ing", "ping", StringComparison.InvariantCulture);
+
+            //区域无关性
+            string s1 = "encyclopædia";
+            string s2 = "encyclopaedia";
+
+            Assert.Contains(s1, s2, StringComparison.InvariantCulture);
+
+            //设置区为美国：无效
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
+            Assert.Contains(s1, s2, StringComparison.InvariantCulture);
+
+            //设置区为se-SE：无效 
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("se-SE");
+            Assert.Contains(s1, s2, StringComparison.InvariantCulture);
+        }
+
+        [Fact]
+        public void Contains_String_Comparison_InvariantCultureIgnoreCase_Test()
+        {
+            //StringComparison.InvariantCultureIgnoreCase与StringComparison.InvariantCulture，只是忽略大小写
+
+            Assert.Contains("ping", "PinG", StringComparison.InvariantCultureIgnoreCase);
+            Assert.Contains("p", "PinG", StringComparison.InvariantCultureIgnoreCase);
+            Assert.Contains("in", "PinG", StringComparison.InvariantCultureIgnoreCase);
+            Assert.Contains("ing", "PinG", StringComparison.InvariantCultureIgnoreCase);
+
+            //区域无关性
+            string s1 = "Encyclopædia";
+            string s2 = "encyclopaediA";
+
+            Assert.Contains(s1, s2, StringComparison.InvariantCultureIgnoreCase);
+
+            //设置区为美国：无效
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
+            Assert.Contains(s1, s2, StringComparison.InvariantCultureIgnoreCase);
+
+            //设置区为se-SE：无效 
+            Thread.CurrentThread.CurrentCulture = new CultureInfo("se-SE");
+            Assert.Contains(s1, s2, StringComparison.InvariantCultureIgnoreCase);
         }
+        #endregion
+
+        #region Contains Collection
+        [Fact]
+        public void Contains_Generic_In_IEnumerable_Test()
+        {
+            //字符数组
+            var stringArray = new List<string>() { "first", "second", "third", "four" };
+            Assert.Contains<string>("first", stringArray);
+            Assert //可以简化写法
+                   .Contains("second", stringArray);
+
+            //int 数组
+            var intArray = new List<int>() { 1, 2, 3, 4, 5 };
+            Assert.Contains<int>(2, intArray);
+            Assert //可以简化写法
+                   .Contains(3, intArray);
+
+            //类组
+
+            //内部各项都相等，但实例(引用)不同，则不包含
+            var classArray = new List<Person>()
+            {
+                new Person(){ Id=1, FirstName="first1", LastName="last1"},
+                new Person(){ Id=2, FirstName="first2", LastName="last2"},
+                new Person(){ Id=3, FirstName="first3", LastName="last3"},
+            };
+
+            Person person1 = new Person() { Id = 1, FirstName = "first1", LastName = "last1" };
+            Person person2 = new Person() { Id = 2, FirstName = "first2", LastName = "last2" };
+            Person person3 = new Person() { Id = 3, FirstName = "first3", LastName = "last3" };
+
+            Assert.DoesNotContain<Person>(person1, classArray);
+            Assert //简化写法
+                   .DoesNotContain(person2, classArray);
+            Assert //简化写法
+                   .DoesNotContain(person3, classArray);
+
+            //相同的引用才包含
+            classArray.Add(person1);
+            classArray.Add(person2);
+            classArray.Add(person3);
+
+            Assert.Contains(person1, classArray);
+            Assert.Contains(person2, classArray);
+            Assert.Contains(person3, classArray);
+
+        }
+
+        [Fact]
+        public void Contains_Generic_In_IEnumerable_IEqualityComparer_Test()
+        {
+            //以 IEqualityComparer 比较器为断言依据
+
+            Person person1 = new Person() { Id = 1, FirstName = "first1", LastName = "last1" };
+            Person person2 = new Person() { Id = 2, FirstName = "first2", LastName = "last2" };
+            Person person3 = new Person() { Id = 3, FirstName = "first3", LastName = "last3" };
+
+            var classArray = new List<Person>()
+            {
+                new Person() { Id = 1, FirstName = "ab", LastName = "cd" },
+                new Person() { Id = 2, FirstName = "ef", LastName = "g" },
+                new Person() { Id = 3, FirstName = "s", LastName = "b" },
+            };
+
+            //自定义比较器
+            IEqualityComparer<Person> equalityComparer = new Person();
+
+            Assert.Contains(person1, classArray, equalityComparer);
+            Assert.Contains(person2, classArray, equalityComparer);
+            Assert.Contains(person3, classArray, equalityComparer);
+        }
+
+        [Fact]
+        public void Contains_Generic_IEnumerable_Filter_Test()
+        {
+            Person person1 = new Person() { Id = 1, FirstName = "first1", LastName = "last1" };
+            Person person2 = new Person() { Id = 2, FirstName = "first2", LastName = "last2" };
+            Person person3 = new Person() { Id = 3, FirstName = "first3", LastName = "last3" };
+
+            var classArray = new List<Person>()
+            {
+                person1,
+                person2,
+                person3,
+            };
+
+            //Predicate<T> 委托（入参T,返回 bool），作为筛选条件
+            Assert.Contains<Person>(classArray, person => person.Id == 1);
+            Assert //简写为
+                   .Contains<Person>(classArray, person => person.FirstName == "first1");
+            Assert //简写为
+                   .Contains<Person>(classArray, person => person.Id == 3 && person.LastName=="last3");
+        }
+
+        [Fact]
+        public void Contains_Generic_In_IDictionary_Test()
+        {
+            //字符串
+            KeyValuePair<string, string> sring_kv1 = new KeyValuePair<string, string>("key1", "first");
+            KeyValuePair<string, string> string_kv2 = new KeyValuePair<string, string>("key2", "second");
+            KeyValuePair<string, string> string_kv3 = new KeyValuePair<string, string>("key3", "third");
+
+            IDictionary<string, string> stringDic = new Dictionary<string, string>();
+            stringDic.Add("key1", "first");
+            stringDic.Add("key2", "second");
+            stringDic.Add("key3", "third");
+
+            Assert.Contains<string,string>("key1", stringDic);
+            Assert.Contains<KeyValuePair<string, string>>(sring_kv1, stringDic);
+
+            //数字
+            KeyValuePair<string, int> int_kv1 = new KeyValuePair<string, int>("key1", 1);
+            KeyValuePair<string, int> int_kv2 = new KeyValuePair<string, int>("key2", 2);
+            KeyValuePair<string, int> int_kv3 = new KeyValuePair<string, int>("key3", 3);
+
+            IDictionary<string, int> intDic = new Dictionary<string, int>();
+            intDic.Add("key1", 1);
+            intDic.Add("key2", 2);
+            intDic.Add("key3", 3);
+
+            Assert.Contains<string,int>("key1", intDic);
+            Assert.Contains<KeyValuePair<string, int>>(int_kv1, intDic);
+
+            //类
+            Person person1 = new Person() { Id=1,FirstName="first1",LastName="last1"};
+            Person person2 = new Person() { Id=2,FirstName="first2",LastName="last2"};
+            Person person3 = new Person() { Id=3,FirstName="first3",LastName="last3"};
+
+            KeyValuePair<string, Person> class_kv1 = new KeyValuePair<string, Person>("key1", person1);
+            KeyValuePair<string, Person> class_kv2 = new KeyValuePair<string, Person>("key2", person2);
+            KeyValuePair<string, Person> class_kv3 = new KeyValuePair<string, Person>("key3", person3);
+
+            IDictionary<string, Person> classDic = new Dictionary<string, Person>();
+            classDic.Add("key1", person1);
+            classDic.Add("key2", person2);
+            classDic.Add("key3", person3);
+
+            Assert.Contains<string,Person>("key1", classDic);
+            Assert.Contains<KeyValuePair<string,Person>>(class_kv1,classDic);
+            Assert.Contains(class_kv2,classDic);
+            Assert.Contains(class_kv3,classDic);
+        }
+
+        [Fact]
+        public void Contains_Generic_In_IReadOnlyDictionary_Test()
+        {
+            //类似 IDictionary
+
+            //字符串
+            KeyValuePair<string, string> sring_kv1 = new KeyValuePair<string, string>("key1", "first");
+            KeyValuePair<string, string> string_kv2 = new KeyValuePair<string, string>("key2", "second");
+            KeyValuePair<string, string> string_kv3 = new KeyValuePair<string, string>("key3", "third");
+
+            IDictionary<string, string> stringDic = new Dictionary<string, string>();
+            stringDic.Add("key1", "first");
+            stringDic.Add("key2", "second");
+            stringDic.Add("key3", "third");
+
+            IReadOnlyDictionary<string,string> stringReadOnlyDic = stringDic as IReadOnlyDictionary<string,string>;
+
+            Assert.Contains<string, string>("key1", stringReadOnlyDic);
+            Assert.Contains<KeyValuePair<string, string>>(sring_kv1, stringReadOnlyDic);
+
+            //类
+            Person person1 = new Person() { Id = 1, FirstName = "first1", LastName = "last1" };
+            Person person2 = new Person() { Id = 2, FirstName = "first2", LastName = "last2" };
+            Person person3 = new Person() { Id = 3, FirstName = "first3", LastName = "last3" };
+
+            KeyValuePair<string, Person> class_kv1 = new KeyValuePair<string, Person>("key1", person1);
+            KeyValuePair<string, Person> class_kv2 = new KeyValuePair<string, Person>("key2", person2);
+            KeyValuePair<string, Person> class_kv3 = new KeyValuePair<string, Person>("key3", person3);
+
+            IDictionary<string, Person> classDic = new Dictionary<string, Person>();
+            classDic.Add("key1", person1);
+            classDic.Add("key2", person2);
+            classDic.Add("key3", person3);
+
+            IReadOnlyDictionary<string,Person> classReadOnlyDic = classDic as IReadOnlyDictionary<string,Person>;
+
+            Assert.Contains<string, Person>("key1", classReadOnlyDic);
+            Assert.Contains<KeyValuePair<string, Person>>(class_kv1, classReadOnlyDic);
+            Assert.Contains(class_kv2, classReadOnlyDic);
+            Assert.Contains(class_kv3,classReadOnlyDic);
+
+        }
+        #endregion
 
         [Fact]
         public void All_Test()